This is the first time I've seen this in my pictures and can't quite figure out what it is / how it fix it / or how to avoid it in the future. Was wondering if anyone here had any ideas?
The thing in question are those speckled bits on the buildings and a few red ones in the sky on the left.
After a bit of research, I thought maybe they are hot pixels (never encounter them before either, just looked up about them recently), but in my other shots, those pixels in those locations are fine nor do they shot up in other similar shots (or at least I don't notice them). They seem to be fixed to that location on the building regardless of position/zoom.
Another example of them, though this one has less (cropped from a larger picture, but it was from the middle of the shot extending to the right of the frame).
Between the two shots, these buildings were roughly 90 degrees relative to me on opposite shores, so I doubt it is some crazy reflection from somewhere.
I'm using a canon 550d (T2i) and the first picture taken 5" shutter, iso400, and F5.6. The second picture is similar: 6", iso400, F4. Both using kit lens (18-55mm) on a tripod with no filter on. Both those pictures were also from a set of bracketed shots and the spekcles show up in all of them in the same places at slightly different brightnesses. Exposures went from 1.3" to 20" and 1.6" to 25" with everything else was fixed. Was also shooting in raw.
If it mattered, an hour or two before, I was shooting in near pitch black (no bright light sources) with up to 150" exposures. No issues in those shots though.
Added links to the full res pictures:
First image: https://i.stack.imgur.com/ZgMJ8.jpg
Second image: https://i.stack.imgur.com/TphmU.jpg
First image again at +2 exposure: https://i.stack.imgur.com/EESh6.jpg